Raman spectroscopy analysis of Palaeolithic industry from Guadalteba terrace river, Campillos (Guadalteba county, Southern of Iberian Peninsula)

摘要

A representative set of eight lithic tools suitably selected among the very rich Palaeolithic industry collected over the past years in different archaeological sites of the Guadalteba County (Málaga, Spain) has been nondestructively investigated by means of Raman spectroscopy using both portable and benchtop Raman spectrometers. This article reports on the first archaeometric Raman analysis of these archaeological samples with the scope of checking if these readily available, nondestructive, fast and cheap vibrational spectroscopic techniques, which in addition do not require a preliminary sample preparation, could provide any meaningful information for characterizing the mineral composition of chert artefacts and ultimately some specific arguments about their assignment to distinctive groups of raw materials of a particular provenance. On the basis of the vibrational data, it was confirmed that α-quartz was the raw material in all the cases, although a small amount of moganite was also evidenced as a distinctive fingerprint in these chert samples. On the other hand, crusts were mainly made of calcite in all the cases, sometimes accompanied by other minerals such as barite or anatase. This first Raman spectroscopic study on chert and sandstone artefacts from the Guadalteba county reveals that there are good premises for a further and more thorough archaeometric investigation of these lithic tools based on sets of Raman measurements (Raman mapping) on each specimen rather than on single-point Raman experiments such as in the present case, given the wide macroscopic heterogeneity of this kind of samples (colour, grain size, transparency, etc.). The Raman-mapping archaeometric analyses of bulks and crusts would be also complemented with X-ray diffraction and X-ray fluorescence data.